MEPCO SCHLENK ENGINEERING COLLEGE, SIVAKASI DEPARTMENT OF MECHANICAL ENGINEERING
V SEMESTER MECHANICAL ENGINEERING July 2010 to Nov 2010
SUBJECT: ME59 – CAD/CAM LAB
LABORATORY MANUAL
Prepared by
Approved by
Dr.T.Prabaharan Professor / Mech. Dr.R.Rajkumar Professor / Mech.
HOD/Mech.
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SYLLABUS ME59 CAD/CAM LAB LTPC 0032 OBJECTIVES: - To be able to understand and handle design problems in a systematic manner. - To gain practical experience in handling 2D drafting and 3D modeling software systems. - To be able to apply CAD in real life applications. - To understand the concepts G and M codes and manual part programming. - To expose students to modern control systems (Fanuc, Siemens etc) - To know the application of various CNC machines - To expose students to modern CNC application machines EDM, EDM wire cut and Rapid Prototyping UNIT I 3D GEOMETRIC MODELING Creation of 3D Models - Wire Frame, Surface, Solid modeling Techniques Using CAD Packages – CSG, B-Rep Approaches in Solid Modeling - Feature Based Modeling Technique – Assembly – Detailing - Exposure to Industrial Components – Application of GD&T UNIT II STL FILE GENERATION – REVERSE ENGINEERING Manual CNC Part Programming Manual CNC Part Programming Using Standard G and M Codes - Tool Path Simulation – Exposure to Various Standard Control Systems- Machining simple components by Using CNC machines. UNIT III COMPUTER AIDED PART PROGRAMMING CL Data Generation by Using CAM Software– Post Process Generation for Different Control System – Machining of Computer Generated Part Program by Using Machining Center and Turning Center. UNIT IV STUDY OF EXPERIMENTS Multi-axial Machining in CNC Machining Center –EDM – EDM Wire Cut – Rapid Prototyping
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LIST OF EXPERIMENTS
CAD 1. 3D – Part modeling of a component 2. 3D – Part modeling of a component 3. Assembly of Flange coupling in 3D using Solidworks modeling software 4. Assembly of Plummer block in 3D using Solidworks modeling software CAM 1. Milling simulation using CAPSMILL software 2. Turing simulation using CAPSTURN software 3. Turning exercise in Production lathe using single tool 4. Milling exercise in Trainer Milling machine
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TENTATIVE SCHEDULE FOR CAD LAB
Experiment Number
A1BATCH
A2BATCH
B1BATCH
B2BATCH
Date of
Date of
Date of
Date of
Experiment
Record Submission
Experiment
Record Submission
Experiment
Record Submission
Experiment
Record Submission
1
04-Aug-10
01-Sep-10
11-Aug-10
08-Sep-10
02-Aug-10
30-Aug-10
09-Aug-10
06-Sep-10
2
01-Sep-10
29-Sep-10
08-Sep-10
06-Oct-10
30-Aug-10
27-Sep-10
06-Sep-10
04-Oct-10
3
29-Sep-10
13-Oct-10
06-Oct-10
20-Oct-10
27-Sep-10
11-Oct-10
04-Oct-10
18-Oct-10
4
13-Oct-10
27-oct-10
20-Oct-10
03-Nov-10
11-Oct-10
25-Oct-10
18-Oct-10
01-Nov-10
TENTATIVE SCHEDULE FOR CAM LAB
Experiment Number
A1BATCH
A2BATCH
B1BATCH
B2BATCH
Date of
Date of
Date of
Date of
Experiment
Record Submission
Experiment
Record Submission
Experiment
Record Submission
Experiment
Record Submission
1
11-Aug-10
08-Sep-10
04-Aug-10
01-Sep-10
09-Aug-10
06-Sep-10
02-Aug-10
30-Aug-10
2
08-Sep-10
06-Oct-10
01-Sep-10
29-Sep-10
06-Sep-10
04-Oct-10
30-Aug-10
27-Sep-10
3
06-Oct-10
20-Oct-10
29-Sep-10
13-Oct-10
04-Oct-10
18-Oct-10
27-Sep-10
11-Oct-10
4
20-Oct-10
03-Nov-10
13-Oct-10
27-Oct-10
18-Oct-10
01-Nov-10
11-Oct-10
25-Oct-10
Batch
Roll Number
A1BATCH
08M01 – 08M16
A2BATCH
08M17 – 08M33
B1BATCH
08M34 – 08M49
B2BATCH
08M50 – 08M60 and 08ML01 - 08ML06
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INSTRUCTIONS TO STUDENTS 1.
Students are required to remove their footwear outside the center and keep it in the box provided for the same.
2.
Students should leave their belongings outside the lab except their observation note book, the concerned books/manuals and calculators.
3.
Students are requested not to place their legs on the wall or on the table.
4.
Students should refrain from leaning on the table and sitting on it.
5.
Before logging in to a particular terminal, if there is something wrong in the terminal, the student should report the same immediately to the concerned staff.
6.
Students should not use any disks brought from outside without prior permission from the concerned staff.
7.
Students can get the required manual or disks from the staff after signing in the appropriate register.
8.
Students should collect their printouts before leaving the lab for that particular session.
9.
Before leaving the Terminal, the students should logout properly and leave their chairs in position.
10.
Students are not allowed to take any manual outside the center.
11.
Edibles are strictly prohibited in the center.
12.
No internet browsing allowed during the lab hours. ******
IMPORTANT INSTRUCTIONS TO HANDLE CNC MACHINES 1. Get permission from the concerned staff before switch ON the CNC machines. 2. Ensure the proper power supply for the system and machine. 3. Handle the CNC machines very carefully. 4. If any problem occurs in the system or machine immediately inform to the concerned staff. Don’t try to rectify the problem by yourself. 5. Your batch is responsible for the CNC machine and its system while doing the lab exercise assigned to your batch. ****** 5
CONTENTS Sl. No.
ITEMS
Page No.
A) COMPUTER AIDED DESIGN (CAD) 1.
Design process and Role of CAD
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2.
Solid modeling
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3.
Requirements for Modeling Assembly
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4.
CADCAE/CAM Data Exchange
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5.
Solid Works software overview
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6.
Exercises in 3D Part Modeling
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7.
Exercises in Assembly
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8.
Additional Exercises in Part Modeling and Assembly
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B) COMPUTER AIDED MANUFACTURING (CAM) Manual Part Programming in CNC Lathe 9.
Programming in CNC 250 Production Lathe
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10.
Exercise in Production Lathe using Single Tool
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11.
Exercise in Production Lathe using Multi Tool
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Manual Part Programming in CNC Milling 12.
Linear, Circular Interpolation and Pocketing
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13.
Exercises in Linear, Circular Interpolation and Pocketing
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C) SIMULATION AND NC CODE GENERATION 14. 15.
LATHE SIMULATION – CL and NC Code generation using CAPSTURN software MILLING SIMULATION – CL and NC Code generation using CAPSMILL software
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A) COMPUTER AIDED DESIGN (CAD) 1. DESIGN PROCESS AND ROLE OF CAD According to Shigley, the design process is an iterative procedure involving the following six phases: 1. Recognition of need 2. Definition of problem 3. Synthesis 4. Analysis and optimization 5. Evaluation 6. Presentation Phase 3 (synthesis) includes defining the design problem, design conceptualization, searching for design information, modeling and simulation. Phase 4 (analysis and optimization) may includes parameter study, finite element analysis, etc. Although computers are being utilized more and more in the design process, their use is still limited to the last four steps in the design and they are mainly used as a tool that helps the designer, rather than as a replacement for the designer. Benefits of Using CAD: (1) Increasing productivity (2) Improving quality of design (3) Improving communications (4) Creating data-base for manufacturing The Design Process and Computer-Aided Design Design Process
Computer Aided Design
Fig. 1.1 – Role of computers in design process
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Geometric Modeling The term geometric modeling (or representation) means a method of describing commonly used curves and surfaces in terms of values of a few parameters. Three Types of Geometric Models Wireframe Model : connect 3D vertex points, sometimes ambiguous. Surface Model : define surface to form an object. Solid Model : various representation schemes are used to describe a solid object 2. SOLID MODELING A solid modeling system is usually an interactive computer graphics system that is intended to create true three-dimensional components and assemblies. Recent advances in CAD software, computers, and graphical displays have made it possible to use solid representations of components being considered in the design process. These solid models can be employed in numerous ways. Advantages of Solid Modeling A realistic visual display: By producing a shaded visible surface image of the solid, solid modeling allows a designer to see exactly what has been created. Easy to deal with different views: Once a part has been created, we have the ability to rotate, shade, section, or produce almost any view required by a designer. Single associated model database: The solid modeler provides the only database suitable for all CAD operations. Almost all information needed for part generation is contained in the solid model. The algorithm should be able to ensure that it represents physically possible shape that is complete and unambiguous Applications. e.g., automatic generation of a mesh for a finite element analysis. 3. REQUIREMENTS FOR MODELING ASSEMBLING 1. Part modeling and analysis The part analysis include the material type, mass and inertial properties, functional properties of the faces, etc. 2. Hierarchical relationships An assemble tree and assemble sequence must be given. 3. Mating conditions. There are two methods for specifying mating conditions: Specify the location and orientation of each part in the assembly, together with the representation of the part itself, by providing a 4 x 4 homogeneous transformation matrix. (i.e., transformation from MCS to WCS) Specify the spatial relationships between its individual parts as mating conditions. For example, a mating condition can consist of planar faces butting up against one another or requiring centerlines of individual parts to be collinear (―fits‖ condition).
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4. CADCAE/CAM Data Exchange Computer databases are now replacing paper blueprints in defining product geometry and non-geometry for all phases of product design, analysis, and manufacturing. It becomes increasingly important to find effective procedures for transferring data among CAD/CAE/CAM systems. The need to exchange modeling data is directly motivated by the need to integrate and automate the design and manufacturing process to obtain the maximum benefits from CAD/CAE/CAM systems. Four Types of Modeling Data to be Transferred: (1) Shape (2) Nonshape (3) Design (4) Manufacturing (1) Shape data consists of both geometrical and topological information as well as part features. Entity attributes such as font, color, and layer as well as annotation are considered part of the entity geometrical information. Topological information applies only to products described via solid modeling. Features allow high-level concept communication about parts. Examples are hole, flange, web, pocket, chamfer, etc. (2) Nonshape data includes graphics data such as shaded images, and model global data as measuring units of the database and the resolution of storing the database numerical values. (3) Design data has to do with the information that designers generate from geometric models for analysis purposes. e.g., mass property and finite element mesh data. (4) Manufacturing data consists of information such as tooling, NC tool paths, tolerancing, process planning, tool design, and bill of materials. Commonly Used CAD Data Exchange Format IGES (Initial Graphics Exchange Specification) PDES (Product Data Exchange Using STEP) IGES is focused on CAD-to-CAD exchange where primarily shape and nonshape data were to be transferred from one system to another. PDES is previous called Product Data Exchange Standard. It is for the exchange of complete product descriptions which covers the four types of modeling data (i.e., shape, nonshape, design and manufacturing). Other data exchange interfaces include: STL, Neutral, SET, ECAD, VDA, STEP, PDGS, CATIA, Render, CGM, VRML, PATRAN, TIFF, etc.
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5. SOLID WORKS SOFTWARE OVERVIEW Solid Works is a computer-aided design (CAD) system for mechanical assembly, part modeling, and drawing production. Developed with STREAM technology, Solid Works is designed to increase software performance with an interface that ensures maximized user productivity and return on investment. Solid Works STREAM technology boosts essential CAD user productivity by capturing engineers' solid modeling design intentions through inference logic and decision-management concepts. STREAM technology makes Solid Works easy to learn, easy to use, and more productive than any other mid-range CAD system on the market. The Part Environment: The Solid Works part modeling environment allows you to construct 3-D solid models with true features. The part modeling process starts with a base feature, such as a block or cylinder, which you build upon with part features to create a part model. Part features include protrusions and cutouts (extruded, revolved, swept, and lofted), holes, ribs, thin-walled solids, rounds, draft angles, and chamfers. You can also construct rectangular and circular feature patterns and mirror copies. When you design parts in Solid Works, all geometry is created in the context of constructing features. The software keeps track of construction elements for you, making them available when you edit the feature but hiding them from view while you work on other parts of the design. You can also add your own construction geometry, such as extruded, lofted, and swept surfaces, intersection curves, projected curves, and intersection points. The Assembly Environment: Solid Works can manage large, complex assemblies containing many parts and subassemblies. The Assembly environment contains commands for fitting parts together with natural assembly techniques such as mate and aligns. Solid Works accommodates the fact that most parts are designed in the context of an assembly. To support this workflow, Solid Works provides tight integration with the part modeling environment, visualization tools, data management tools, and part-to-part relationship management tools. Solid Works makes it easy to manage assembly data from the earliest phases of project planning, through revision cycles, manufacturing, project maintenance, and archival. The Draft Environment: Solid Works provides a separate drafting environment for producing engineering drawings directly from 3-D part or assembly models. Solid Works drawings are associated with the 3-D model, so that the drawing reflects changes in the model as the design progresses. These modelto-drawing links minimize drawing maintenance in response to engineering changes, so that you can easily keep drawings up-to-date with the part or assembly model. Hidden line representations are properties of the drawing view—they do not affect your view of the solid model in the Part or Assembly environments. You can create drawings that display various views, sections, details, dimensions, notes, and annotations. You can also add feature control frames, datum frames, weld symbols, and surface texture symbols to your drawings. Ensuring that the dimensions and annotations on your drawings conform to your company’s standards or international standards is easy—as in Microsoft Office products, you can capture these settings in styles and templates.
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Base Features in Part Modeling Extrude: Extension in third axis of the profile
Revolve
Fig. 5.1 : Revolve the profile about axis of symmetry
Sweep
Fig. 5.2 : Extrusion of a cross section along a path
Blend / Loft
Fig. 5.3 : Blending of different cross sections along a path
Fig. 5.4 11
Editing & Engineering Features in Part Modeling Round : Modify the sharp edge to curved edge Chamfer
: Modify the sharp edge to flat edge
Shell
: Removes a surface or surfaces from the solid then hollows out the inside of the solid, leaving a shell of a specified wall thickness.
Rib
: Special type of protrusion to create a thin fin or web
Cut
: Remove the undesirable portion from the basic part
Fig. 5.5 Hole
: Remove cylindrical portion from the basic part
Fig. 5.6 Pattern
: Create instances of the selected feature by varying some specified dimensions
Fig. 5.7
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6. PART MODELING AND ASSEMBLY IN SOLID WORKS Important steps 1. Choose the best profile for sketching. 2. Choose the proper sketch plane. 3. Create a new part. 4. Create a sketch. 5. Extrude a sketch as a boss. 6. Extrude a sketch as a cut. 7. Create Hole Wizard holes. 8. Insert fillets on a solid. 9. Make a basic drawing of a part. 10. Make a change to a dimension. 11. Demonstrate the associatively between the model and its drawings. Terminology Moving to 3D requires some new terminology. The SolidWorks software employs many terms that you will become familiar with through using the product. Many are terms that you will recognize from design and manufacturing such as cuts and bosses. Feature All cuts, bosses, planes and sketches that you create are considered Features. Sketched features are those based on sketches (boss and cut), applied features are based on edges or faces (fillet). Plane Planes are flat and infinite. They are represented on the screen with visible edges. They are used as the primary sketch surface for creating boss and cut features. Parallel Plane Creates a reference plane parallel to a part face or reference plane at an offset value you define. You can define the offset value using the cursor or by typing a value in the Distance box on the ribbon bar.
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Sketch In the SolidWorks system, the name used to describe a 2D profile is sketch. Sketches are created on flat faces and planes within the model. They are generally used as the basis for bosses and cuts, although they can exist independently. Extrusion Boss/ Base Although there are many ways to create features and shape the solid, for this lesson, only extrusions will be discussed. An extrusion will extend a profile along a path normal to the profile plane for some distance. The movement along that path becomes the solid model.
Extruded cutout A Cut is used to remove material from the model. This is the opposite of the boss. Like the boss, cuts begin as 2D sketches and remove material by extrusion, revolution, or other methods.
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Revolved Boss/ Base Constructs a protrusion by revolving a profile To create a revolve feature: 1. Create a sketch that contains one or more profiles and a centerline, line, or edge to use as the axis around which the feature revolves. 2. Click one of the following revolve tools: Revolved Boss/Base Revolved Surface
on the Features toolbar, or Insert, Boss/Base, Revolve on the Surfaces toolbar, or Insert, Surface, Revolve
3. In the Property Manager, set the options. 4. Click OK.
Lofted Boss/ Base Constructs a protrusion by fitting through a series of cross sections. You can define the cross sections using profiles drawn within the command, sketches, or edges of existing features. The cross sections must be closed, planar elements.
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View Options SolidWorks gives you the option of representing your solid models in one of several different ways. They are listed below, with their icons: Symbol Description Shaded
Shaded with Edges Hidden Lines Removed Hidden Lines Visible Wireframe
Examples of each are shown in the illustration below
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BASIC FEATURES Extrude Revolve Sweep Blend / Loft
: Extension in third axis of the profile : Revolve the profile about axis of symmetry : Extrusion of a cross section along a path : Blending of different cross sections along a path
CREATION OF BASIC SOLID FEATURES EXTRUDE
Insert (from menu bar) > Select Extrude > Click Sketcher icon (from dash board) > Select a plane (from main window) > Click Sketch (from section dialogue box) > Select References (check reference status fully placed) > Close (reference dialogue box) > Sketch a figure (edit dimensions if required) > Click (blue color to continue) > Enter depth value (at prompt in dash board) > click preview (at dash board) > click (green color on dash board) > file > save > click (green color)
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REVOLVE
Insert > Revolve > Select Sketcher (icon from dash board) > Select plane for sketching > Click sketch > Select References > Close reference > Draw figure > Draw centre line as axis (along which it should revolve) > Click (blue color) > Specify angle (in dash board upto which it should rotate) > preview > click (green color) SWEEP
Insert > Sweep > Protrusion > Click Sketch Trajectory (from sweep trajectory menu manager) > Select a Plane > Okay (for direction) > Default (sketch view) > Select References > Close (reference dialogue box) > Draw Trajectory > Click (blue color) > Sketch Cross section (at the intersection of two yellow color axes) > Click (blue color) > Preview > OK (to accept)
BLEND
Insert > Blend > Protrusion > (from blend options) Select Parallel > Regular section > Sketch section > Done > (from Attributes) Select Straight > Done > (from Set up plane) Select a Plane > Okay (direction) > Default (sketch view) > Select References (check whether it is fully placed) > Close (reference dialogue box) > Draw section 1 > Right click mouse and select Toggle section > Draw section 2 > Click (blue color to continue) > Enter depth value at prompt (between section 1 and 2) and click (green color) > Preview (from Protrusion dialogue box) > OK (to accept drawing) 18
EDITING & ENGINEERING FEATURES
Round Chamfer Cut Hole Pattern
: Modify the sharp edge to curved edge : Modify the sharp edge to flat edge : Remove the undesirable portion from the basic part : Remove cylindrical portion from the basic part : Create instances of the selected feature by varying some specified dimensions Shell : Removes a surface or surfaces from the solid then hollows out the inside of the solid, leaving a shell of a specified wall thickness. Rib : Special type of protrusion to create a thin fin or web
Round Inserting Round in Corners: Create a basic feature > Insert > Round > Select an edge or a chain of edges with ctrl key pressed > Enter radius (at prompt in dash board) > Preview > Click (green color to accept) CHAMFER Edge Chamfer: Create a basic feature > Insert > Chamfer > Edge Chamfer > Select Sets option (from dash board) > Select edges (as reference for chamfering with ctrl key pressed) > select one option from dash board (for example D x D) > Enter value for D at prompt) > Preview > Click (green color to accept) CUT
Create a basic feature > Insert > extrude > select sketcher icon > select sketch plane (to insert cut) > click sketch > select references > close (reference dialogue box) > draw a figure > click (blue color) > select type of depth (from dash board) > enter depth value > flip in required > click remove material icon (on the dash board) > click flip direction if required > preview > click (green color on dash board to accept) HOLE Create a basic feature > Insert > Hole > (from dash board) Select Simple > Click Placement > Select a surface (for primary reference) > Select linear > Click No Items under secondary reference > Select 2 edges (with ctrl key pressed) > Enter edge 19
offset values > (In dash board) Enter diameter of hole > Select type of dept > Enter depth value > Preview > Click (green color to accept)
PATTERN Create a basic feature (for example with hold included) > select a part from model tree (example – hole, to be patterned and which is having reference dimensions) > right click mouse on it > select pattern > select dimension option (from dash board) > select 1st reference dimension (from main window by placing cursor on dimension for direction 1) > enter increment value > select 2nd reference dimension (for direction 2) > enter increment value > enter number of items (for direction 1 & 2 at dash board) > click (green color to accept pattern) SHELL Create a basic feature > insert > shell > select surfaces with ctrl key pressed (which are to be shelled) > enter thickness at the prompt > click (green color to accept) RIB Create a basic feature > insert > rib > click sketcher icon > select a plane (along with rib should form) > click sketch > select references > close (reference dialogue box) > draw an open section for rib formation > click (blue color to continue) > specify thickness of the rib (at prompt) > flip direction (if required at prompt and also flip direction on screen to face inside) > preview > click (green color to accept drawing)
ASSEMBLY OPERATION ASSEMBLY CONSTRAINTS Mate Mate constraint two surfaces touch one another, coincident and facing each other shown in fig.
Mate Offset Mate offset constraint makes two planar surfaces parallel and facing each other. The offset value determines the distance between two surfaces shown in fig.
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Align Align constraint makes two planes coplanar, coincident and facing in the same direction. It also aligns revolved surfaces or axes to make them coaxial shown in fig.
Align Offset This constraint aligns two planar surfaces at an offset, parallel and facing in the same direction shown in fig.
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Insert Insert constraint inserts a male revolved surface into a female revolved surface, align axes shown in fig. 1.17.
Orient The orient constraint orients two planar surfaces so that they are parallel and facing in the same direction, offset is not specified. See fig. 1.18.
Coord Sys The coordinate system constraint places a component in an assembly by aligning its coordinate system with a coordinate system in the assembly shown in fig.
Tangent The Tangent, pnt on line, pnt on surface and Edge on srf constraints are used to control the contact of a surface at the tangency of another surface, at a point or at an edge. In most cases, a combination of the constraints will be required.
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6. EXERCISES IN 3D PART MODELING
Fig. 6.1
Fig. 6.2
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Fig. 6.3
Fig. 6.4
Fig. 6.5
Fig. 6.6
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Fig. 6.7
Fig. 6.8
25
7. EXERCISES IN ASSEMBLY
Fig. 7.1 26
Fig. 7.2
27
8. ADDITIONAL EXERCISES IN PART MODELING
Fig. 8.1
Fig. 8.2 28
ADDITIONAL EXERCISE IN ASSEMBLY MODELING
Fig. 8.3 29
B) COMPUTER AIDED MANUFACTURING (CAM) Manual Part Programming in CNC Lathe 9. PROGRAMMING IN CNC 250 PRODUCTION LATHE Preparatory Functions G00 – Rapid Traverse G01 – Linear Interpolation (Cutting feed) G02 – Circular Interpolation (Clockwise) G03 – Circular Interpolation (Counter Clockwise) G04 – Dwell G28 – Return to Machine reference position G40 – Tool nose radius compensation cancel G41 – Tool nose radius compensation left G42 – Tool nose radius compensation right G50 – Maximum spindle speed setting / Coordinate system setting G70 – Finishing cycle G71 – Turning cycle (Rough) G72 – Facing cycle G73 – Pattern repeating cycle G74 – End face peck drilling G75 – Outer diameter / Internal diameter drilling G76 – Multiple thread cutting G96 – Constant surface speed G97 – Constant surface speed cancel (constant rpm) G98 – Feed per minute G99 – Feed per revolution Miscellaneous functions M00 – Program stop M01 – Optional stop M03 – Spindle clockwise M04 – Spindle counter clockwise M05 – Spindle halt M08 – Coolant on M09 – Coolant off M10 – Chuck or collet close M11 – Chuck or collet open M30 – Program End M40 – Chuck outer clamping M41 – Chuck inner clamping Syntax G00 G01 G02 G03
X X X X
Z ; Z Z Z
F ; R R
F ; F ; 30
G04 X ; G28 U G70 P P – Start sequence Q – End sequence F – Feed
(Time in seconds) W ; Q
F ;
G71 U R ; G71 P Q u w F ; U – Depth of cut R – Relief in X direction P – Start sequence Q – End sequence u – Stock amount for finish – X axis Finishing allowance w – Stock amount for finish – Z axis F – Feed G72 G72
W P
R ; Q
W
F ;
G73 U W R ; G73 P Q u w F ; U – Depth of cut W – Relief in Z direction R – Number of passes P – Start sequence Q – End sequence u – Stock amount for finish – X axis Finishing allowance w – Stock amount for finish – Z axis F – Feed G74 G74
R ; Z
Q
F
G75 G75
R ; X
Z
P
;
G76 P Q R ; G76 X Z q P – Number of idle passes Q – First pass depth of cut R – Relief X – Thread minor dia Z – Thread Length q – Second pass depth of cut p – Thread height F – Pitch
Q
F ;
p
F ;
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10. EXERCISE IN PRODUCTION LATHE USING SINGLE TOOL AIM: To write, simulate and execute a CNC program for the job of given dimensions as shown in the figure using CNC 250 – Production lathe. PROCEDURE: - Initially draw the rough diagram with required dimensions - Write a CNC program with preparatory and miscellaneous codes - Provide proper tolerances to protect the tool - Select appropriate tool - Enter the program using software - Simulation of tool path - Do manual setting - Enable work piece reference and carryout machining RESULT: -
Verify the tool path generation and actual dimensions obtained.
Fig. 10.1
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11. EXERCISE IN PRODUCTION LATHE USING MULTI TOOL AIM: To write, simulate and execute a CNC program for the job of given dimensions as shown in the figure using CNC 250 – Production lathe. PROCEDURE: - Initially draw the rough diagram with required dimensions - Write a CNC program with preparatory and miscellaneous codes - Provide proper tolerances to protect the tool - Select appropriate tool - Enter the program using software - Simulation of tool path - Do manual setting - Enable work piece reference and carryout machining RESULT: -
Verify the tool path generation and actual dimensions obtained.
Fig. 11.1
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Manual Part Programming in CNC Milling 12. LINEAR, CIRCULAR INTERPOLATION AND POCKETING Machine Configuration Model Make Working Table Size Longitudinal Traverse [X] Cross Traverse [Y] Head Traverse [Z] Accuracy
: Star Mill with ATC : MTAB : 360mm x 130mm : 160mm : 90mm : 115mm : 0.001mm
Directives [BILLET - Define Billet Size [EDGEMOVE - Offset from the program zero to the lower left corner of the billet [TOOLDEF - Define diameter and length of a tool [STEP - Step by step execution of program [NOSTEP - Cancel step by step execution of program [SHOW - Show the operation being simulated [NOSHOW - Stop the operation being simulated !TUTORIAL - To display user interactive message at the bottom [CLEAR - It will clear the interactive message display General Notations X X coordinate value Y Y coordinate value Z Z coordinate value D Diameter of tool T Tool Number F Feed rate S Spindle speed R Radius of arc G functions Function G00 G01 G02 G03 G04 G20 G21 G28 G40 G41 G42 G49 G90
Operation Positioning (Rapid traverse) Linear interpolation (Cutting feed) Circular interpolation / Helical CW Circular interpolation / Helical CCW Dwell Exact stop Imperial units (inches) Metric units (mm) Return to reference point Tool radius compensation cancel Left hand radius compensation Right hand radius compensation Tool length compensation cancel Absolute command 34
Function G91 G92 G94 G95 G170-G171 G172-G173
Operation Incremental command Set datum Feed per minute Feed per rotation Circular Pocketing Rectangular Pocketing
M functions Function M00 M02 M03 M04 M05 M06 M70 M71 M80 M81 M98 M99
Operation Program Stop Program End Spindle Forward Spindle Reverse Spindle Stop Tool Change X Mirror on Y Mirror on X Mirror Off Y Mirror Off Subprogram Call Subprogram Exit
13. EXERCISES IN LINEAR, CIRCULAR INTERPOLATION AND POCKETING Aim 1. Writing a NC program for the given profile as shown in the figure. 2. Simulating and executing the program using FANUC Milling software. Procedure - Identify the required coordinates of the profile based on profile origin. - Provide proper tolerances to protect the tool - Select appropriate tool, speed, feed rate for the operations - Write the NC program using appropriate Preparatory and miscellaneous codes. - Enter the program - Analyse the program - ensure the program should be free from errors using check syntax and dry run - Simulate the program - Do manual setting carefully - Carryout machining
Result The dimensions of machined part are verified with drawing. 35
Fig. 13.1
Fig. 13.2 c
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C) SIMULATION AND NC CODE GENERATION 14. LATHE SIMULATION – CL AND NC CODE GENERATION USING CAPSTURN SOFTWARE
Fig. 14.1 Aim To generate NC code for the given profile using CAPSTURN software. Procedure Work setup Draw the Part Define the Part Draw the Blank Define the Blank Machine the Part View tool path Select a machine Generate NC Program Result Thus the NC code was generated for the given profile using the CAPSTURN software.
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15. MILLING SIMULATION – CL and NC Code generation using CAPSMILL software
All dimensions are in mm Fig. 15.1
Aim To generate NC code for the given profile using CAPSMILL software. Procedure Work setup Draw the Part Define the Part Draw the Blank Define the Blank Machine the Part View tool path Select a machine Generate NC Program Result Thus the NC code was generated for the given profile using the CAPSMILL software.
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